Memory and the fossil record – laboured analogy time

It occurred to me the other evening that the human memory can serve as quite a good analogy for the fossil record. While I have before covered some of the issues of bias in the fossil record, this might serve as something a little easier to think about since it’s based on something we all experience. Anyway, I’ll launch in and see how far I get before the whole edifice breaks down…
So the analogy – the personal memory of humans is like the fossil record. We can start with this instant, now, being the present (which conveniently it is). You can remember pretty much everything that happened in the last two minutes (I would hope) with great accuracy and also great detail. Your memory of this morning should be pretty good too, but perhaps not as detailed. Yesterday, not so hot, two weeks ago – getting tricky, six months ago – ah. In other words, the further back in time you try to remember the less detailed and comprehensive your memories will be. Your memory is constantly being added to at the front end as time passes and degrading behind the present and things sink into the past.

However, despite this, like the fossil record there are still lots of memories going a long way back. You can probably recall quite a few things from say 2004 with some detail, even if they are odd and incidental. What’s more there are still a few things you can recall with incredible clarity from even a very long time ago (I have a couple of crystal clear memories of some incidents when I was only 3 or 4 which I can describe in detail) and patches of a few days or weeks where you can remember a lot interspersed with years of little recollection.

Like the fossil record there are all kinds of little bits of information that could be teased out over time and things that link together and make sense in the context of others. Similarly, the absence of even big stretches of time in your memory does not mean things were not happening – you might not see a friend for several years but you know he was around in 1999 and 2006 so he was still alive in the meantime, even if you have no record of it. And just because you only knew him from the age of 11-18 at school does not mean that he was only alive between those times – he was around before then and afterwards.

At this point this start to get tenuous, but overall I think this paints and handy and useful little picture of the rock record of life on Earth and how we can should consider it.